Day 11

[advent-of-code-18.git] / src / advent11 / advent11-naive.hs

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+{-# LANGUAGE OverloadedStrings #-}
+
+import Data.List
+import qualified Data.Map.Strict as M
+import Data.Map.Strict ((!))
+-- import qualified Data.Set as S
+-- import Data.Function (on)
+import Data.Ord (comparing)
+
+type Coord = (Integer, Integer) -- x, y
+type Grid = M.Map Coord Integer
+
+key = 5719
+-- key = 42
+
+main :: IO ()
+main = do 
+        let g = makeGrid key
+        print $ part1 g
+        print $ part2 g
+
+
+part1 grid = keyOfMaxValue sg
+    where sg = allSubCellPower 3 grid
+
+
+part2 grid = maximumBy (comparing snd) $ [bestInGrid size grid | size <- [3..300]]
+
+-- bestSubCell size grid = 
+
+makeGrid :: Integer -> Grid
+makeGrid key = M.fromList [((x, y), powerLevel x y key) | x <- [1..300], y <- [1..300] ]
+
+powerLevel :: Integer -> Integer -> Integer -> Integer
+powerLevel x y key = ((interim `div` 100) `mod` 10) - 5
+    where rackID = x + 10
+          interim = ((rackID) * y + key) * rackID
+
+subCellPower :: Integer -> Integer -> Integer -> Grid -> Integer
+subCellPower size x y grid = sum [grid!(sx, sy) | sx <- [x..(x+size-1)], sy <- [y..(y+size-1)]]
+
+allSubCellPower :: Integer -> Grid -> Grid
+allSubCellPower size grid = M.fromList [((x, y), subCellPower size x y grid)| x <- [1..(301-size)], y <- [1..(301-size)]]
+
+
+keyAndMaxValue :: Ord b => M.Map a b -> (a, b)
+keyAndMaxValue m = M.foldrWithKey mergeKV (M.findMin m) m
+    where mergeKV k v (bestK, bestV) = 
+            if v > bestV then (k, v) else (bestK, bestV)
+
+keyOfMaxValue :: Ord b => M.Map a b -> a
+keyOfMaxValue m = fst $ keyAndMaxValue m
+
+bestInGrid :: Integer -> Grid -> ((Integer, Integer, Integer), Integer)
+bestInGrid size grid = ((x, y, size), p)
+    where ((x, y), p) = keyAndMaxValue $ allSubCellPower size grid